Captain Obvious

Or.... My next thought is that maybe there's something wrong with your AFM. Hahaha!!! Yeah. me either. Glad you got it working. And all the other work you did will only help moving forward. So were the numbers on the rebuilt AFM correct? Was it the "right" AFM for the year and all?

Interesting... Pretty much everything sounds like it's working OK, but the engine is starving for fuel once you get above idle. So to answer some questions: Yes, it is possible for the EGR to be stuck open even if there's no vacuum applied. But that would cause an issue across all operation conditions, especially idle. If the EGR is stuck wide open, I doubt you'd be able to get a steady idle at all. Same for the PCV if it were stuck open. Sounds like a classic fuel capacity issue, but your fuel pressure up at the rail is OK. Maybe your fuel injectors are partially clogged? They can pass enough fuel at idle (because the engine just doesn't need that much fuel at idle), but when you're taxing them to pass more fuel than that, they can't. There are little screen filter cups on the inlets to the fuel injectors. Maybe they are partially plugged with crud? Maybe the injectors themselves are plugged, or sticky, or both? I'm not sure your conclusions are valid. You're running a tiny bit rich at idle (12.7 - 13.0) which is fine, but just because you can sometimes nurse it up to 3500 doesn't mean you've really got the flow capacity. An engine with no load will "run" with an extremely lean mixture. What's the A/F ratio when you manage to nurse it to 3500? To me, it sounds like you're a little rich at idle, and as the RPM's go up, you get a little leaner, and a little leaner, and a little leaner, until it's finally so lean that it just won't run at all.

I've got one of those too. Not nearly as clean, but works fine. Honestly though, my current go-to is my "old" Harbor Freight trickle charger. It's pretty much a constant current source limited to about 1/2 Amp up to about 12.5 Volts, and then drops the current off above that. By the time you get to 14V it'll give the battery whatever it'll take (which is usually in the milliamp range). At one point, I burned it up. Not sure how, but I let the smoke out. So I figured (since they're disposable) that I would just buy a replacement at HF. Well unfortunately, it turns out that they changed the design... The "old" one still has a step-down transformer in the wall-wart, but the "new" one is a semi-conductor switcher like the other new junk. Hated it. (Men On Film). I mean, don't get me wrong... it's all cheap Chinese junk. But the older junk is better than the newer junk. They took most of the copper out and replaced it with Silicon. So in the end, I reverse engineered my "old" HF charger and fixed it. Anyone surprised? Here's the old one all fixed and also sporting a potentiometer mod to adjust the output voltage: And here's the new one. Flyback switcher with opto-coupler feedback loop. Don't like it at all:

What the old chargers did with a lot of copper and iron (in the form of a transformer), the new ones do with semiconductors. And in today's age, silicon is a lot cheaper than copper. So the bottom line is that most of the new chargers now have silicon components where the old transformers used to be. The way of the world. Lightweight silicon and software instead of heavy copper and capacitors.

So we've known eachother for how many years... And you're just figuring that out? Na-Nu Na-Nu.

I think that since everything is essentially dead ended (or at least should be), there's enough vacuum for everybody. Why don't you "T" a vacuum gauge into the line and drive around like that a little. You'll get a feel for where the vacuum peaks. And if it peaks somewhere other than light cruise, you might need to come up with some sort of alternative. I believe the ignition advance tops out somewhere around 15-20 in Hg. I don't know anything about the big bore TB. Other than it's got a big bore.

I think that the shape of the hole(s) are also as important as the sizes. For example, if I theorize way above my pay grade, I would imagine the shape of the distributor advance goes like this... They wanted a very narrow spike of vacuum oat a specific pedal position, so they used a narrow slit. And I can affirm (from driving around with a vacuum gauge T'd into that line) that the vacuum spike is very narrow and very high (vacuum). The EGR ports on the other hand, appear to be placed to provide vacuum over a much broader pedal position. I'm guessing the smaller hole in the back is used to "extend" the EGR vacuum value deeper into the throttle. So my read on the whole thing is... They optimized the ignition advance to kick in only at one narrow pedal position (light cruise), but the EGR is activated over a broader range and deeper into the pedal (medium cruise). But, neither of those ports will produce any significant vacuum once you get above medium cruise.

As Site mentioned above, the original throttle body has two ported vacuum sources. One for the EGR and the other shared by both the carbon can and the distributor vacuum. Here's another pic showing the two vacuum nipples: And about the idea of sharing the same ported source for all three things (distributor, EGR, and vacuum can), it'll "work", but you can tell from the placement and size of the original vacuum holes that Datsun wanted different vacuum profiles for the two different ports. Here's a pic down inside the throat of the original throttle body. The three small holes in the back are for the ported vacuum sources. (The two larger holes in the foreground are for the BCDD). The narrow slit hole on the left is for the distributor and CARB can. And the pair of holes on the right are for the EGR. You can see by looking at the shape, size, and position of the holes, that they will have different vacuum profiles at different pedal positions. Looks like this: So I'm thinking that it'll "work", but the vacuum profiles won't be the same as stock. Then again... Who's to say that your one ported vacuum source is the same as either stock port anyway?

Awesome! Oh... And don't drive. Your dog is so gonna love you when you wake up in the middle of the night with the hot pepper and tequila sweats.

Not sure where you got your numbers, but they are different than what I get when I go directly to the source(s): AR is 24.5 cents per gallon: https://www.dfa.arkansas.gov/images/uploads/exciseTaxOffice/2020MotorFuelsTaxRateAnnouncement.pdf SC is 24 cents per gallon, but will be going up to 26 cents/gal at the beginning of July: https://dor.sc.gov/tax/motor-fuel And yes, while PA is higher, I'm seeing 57.6 cents per gallon: https://www.revenue.pa.gov/GeneralTaxInformation/Tax Rates/Pages/MFT Rates.aspx There is apparently talk in PA about eliminating or reducing the tax: https://www.governor.pa.gov/newsroom/governor-wolf-commits-to-phasing-out-gas-tax-announces-commission-to-develop-funding-solutions/ And I'm not sure what the numbers mean, but here's what I find for CA. I'm not sure if that's 2.25% + .005 + .505 per gallon or what. But here's the chart: https://www.cdtfa.ca.gov/taxes-and-fees/sales-tax-rates-for-fuels.htm They aren't making any more dinosaurs ever again so it's not like it's going to last forever.

Like Site, I'm still a Ramen guy. The Gospel of the Flying Spaghetti Monster says that eating Ramen and dried pastas allows the struggling college student to afford more beer. And since beer is the drink of Pirates (the chosen people), it suggests that the FSM is trying to turn college students back into Pirates. You all been wondering what I'm the Captain of (besides the obvious)? I like beer and I've been known to say "Aaaaargh!" And "Mate... Fetch my brown pants!"

The 260/280 steering column is different than the previous years, but I don't know if they moved the mounting points as part of the changes.

Of course you do. What's not to like? From https://www.spaghettimonster.org/about/ "Religious texts tell us that humans evolved from Pirates. Consider that so-called “science experts” would have us believe humans evolved from primates, pointing towards the shared 99% shared DNA between humans and primates. But humans and Pirates share upwards of 99.9% of DNA. We believe that Pirates were the original Pastafarians and that they were peaceful explorers. It was only due to Christian misinformation that they have an image of outcast criminals today. No one knows what the afterlife really holds, but we are told FSM Heaven has a Beer Volcano and Stripper Factory." A beer volcano and stripper factory? Sign me up!! Can I get a "Ramen?"

I don't know if it's been mentioned, but those /\/\/\/\/\/\ markings probably signify "resistor".

Another opinion? "Ewwwwww!"

Deleted everything I had here before because it was wrong. Here's a pic from ebay with a pair of those in pretty good shape. I think this is what they looked like at one time. Not sure if they changed the color of the rubbery nugget over the years though.

Well as I said, I'm not sure how much difference a quarter turn would make, but just wanted to mention it. As for calibration... Here's a pic of some testing I ran some time ago. Ballpark should operate something like this:

I got my vaccine not only for myself but for my Z friends and everyone else I come into contact with. I want to be part of the solution, not part of the problem. I want to visit with my Z buddies. I want to go to a Zcon and sit with a whole bunch of Jims and not take the risk of giving any of them a potentially deadly illness. And there's a way to make sure I don't. Get my vaccine. I'm all for personal choice as long as it doesn't endanger other people. In other words, if the only person who is put at risk by your personal choice is YOU... Then go for it. But if your choice puts other people at risk that's not cool. You're removing their right to make their own choice by making it for them. "If you're afraid of getting covid, you have a choice... You can choose to stay home." "If you're afraid of getting vaccinated, you have a choice... You can choose to stay home." Here's the difference: If I don't have covid and I go out, I'm not putting anyone else at risk. If I don't have the vaccine and I go out, I AM putting other people at risk.

Oh, and sorry, but I got nothing for your heater cable. Never messed with the 240 stuff.

Yes, by turning that threaded post a quarter turn, you effectively "scrubbed" the two contacts together and hopefully wiped off the oxides that were preventing good connection. I don't know if that would be as effective as cleaning the contacts with a piece of material or not, but you'll find out. One word of concern though... That threaded stud is a calibration device. More pressure on the switch and the gauge runs higher. Lower pressure, the gauge runs lower. I don't know how much of a change in the needle position will result from a quarter turn. Might be noticeable, or it might be so slight as to not really matter. Now that the oxides have been scrubbed, you could probably turn the screw back to where it was to start and the connection would still be good. Do it four or five times and call it a day (if you haven't already)

And lastly, two final thoughts on the whole matter... 1) Do not confuse wearing an AFDB on your head with wearing a colander on your head. Two completely different purposes. One holy, and one unholy (literally). 2) Neither the colander nor an AFDB will do anything to protect against covid, so GO GET YOUR VACCINE!!! Even if you don't think you need it for yourself, do it for all the other people you come into contact with. We're all in this together and if you don't get vaccinated, you're potentially the Petri dish for the virus to mutate. If you want to get back to normal, get your vaccine!!

Well that could explain a lot..... Haha!!

Oh you know I do. That looks like the chip pan on the lathe. You could probably form them into a AFDM (Aluminum Foil Deflector Mullet).

Hmmm... That's an interesting point. I've never carved one completely out of a chunk of solid aluminum. I wonder if that works any better. I'm thinking that the foil is pressed during production thereby compressing the anti-mind control properties closer together, but the billet is hot forged which allows the molecules to form a more regular crystalline structure which may help as well? Maybe we should test them both at a Zcon sometime. I wear one style and @siteunseen can wear the other. Whichever of us acts more out-of-control is obviously the subject of less mind control (duh).

Yes, the regulator switch is similar to a set of points. It doesn't open and close as quickly, and it doesn't handle nearly as much current, but yeah... It's opened and closed an untold number of times over the past 50 years! So that pic I posted is from the front of a 280 gauge with the faceplate removed. On the 280, the faceplate for the fuel/volt is split down the middle and you can take either half off. Two screws and half the faceplate comes out. Here's a pic of the gauge with the plate intact. Take out the two small screws at the bottom and the "VOLT" faceplate comes off revealing the guts insde. Be careful and gentle and make sure you don't bend the needle. Don't know if the 240 is the same, but the 280 looks like this: If SteveJ works up a video, that would be fantastic.